U.S. patent application number 15/573875 was filed with the patent office on 2018-11-01 for use of alcohols containing at least two urethane groups for preparation of polyether polyols.
The applicant listed for this patent is Covestro Deutschland AG. Invention is credited to Jorg Hofmann, Bert Klesczewski, Hartmut Nefzger, Urs Rauwald.
Application Number | 20180312632 15/573875 |
Document ID | / |
Family ID | 53199870 |
Filed Date | 2018-11-01 |
United States Patent
Application |
20180312632 |
Kind Code |
A1 |
Hofmann; Jorg ; et
al. |
November 1, 2018 |
USE OF ALCOHOLS CONTAINING AT LEAST TWO URETHANE GROUPS FOR
PREPARATION OF POLYETHER POLYOLS
Abstract
The present invention relates to a process for preparing
polyether polyols by adding alkylene oxides onto H-functional
starter compounds, characterized in that at least one alcohol
containing at least two urethane groups is used as H-functional
starter compound. The invention further provides the polyether
polyols containing a structural unit of the formula (IV) where
R.sup.1 is linear or branched C.sub.2 to C.sub.24-alkylene which
may optionally be interrupted by heteroatoms such as O, S or N and
may be substituted, preferably CH.sub.2--CH.sub.2 or
CH.sub.2--CH(CH.sub.3), R.sup.2 is linear or branched C.sub.2 to
C.sub.24-alkylene, C.sub.3 to C.sub.24-cycloalkylene, C.sub.4 to
C.sub.24-arylene, C.sub.5 to C.sub.24-aralkylene, C.sub.2 to
C.sub.24-alkenylene, C.sub.2 to C.sub.24-alkynylene, each of which
may optionally by interrupted by heteroatoms such as O, S or N
and/or may each be substituted by alkyl, aryl and/or hydroxyl,
preferably C.sub.2 to CM alkylene, R.sup.3 is H, linear or branched
C.sub.1 to C.sub.24-alkyl, C.sub.3 to C.sub.24-cycloalkyl, C.sub.4
to C.sub.24-aryl, C.sub.5 to C.sub.24-aralkyl, C.sub.2 to
C.sub.24-alkenyl, C.sub.2 to C.sub.24-alkynyl, each of which may
optionally be interrupted by heteroatoms such as O, S or N and/or
each of which may be substituted by alkyl, aryl and/or hydroxyl,
preferably H, R.sup.4, is H, linear or branched O to
C.sub.24-alkyl, C.sub.24-cycloalkyl, C.sub.4 to C.sub.24-aryl,
C.sub.5 to C.sub.24-aralkyl, C.sub.2 to C.sub.24-alkenyl, C.sub.2
to C.sub.24-alkynyl, each of which may be interrupted by
heteroatoms such as O, S or N and/or each of which may be
substituted by alkyl, aryl and/or hydroxyl, preferably H, IV is
linear or branched C.sub.2 to C.sub.24-alkylene which may
optionally be interrupted by heteroatoms such as O, S or N and may
be substituted, preferably CH.sub.2--CH.sub.2 or
CH.sub.2--CH(CH.sub.3), and where R.sup.1 to R.sup.5 may be
identical or different from one another, and the polyether polyols
obtainable by the process according to the invention.
Inventors: |
Hofmann; Jorg; (Krefeld,
DE) ; Rauwald; Urs; (Dusseldorf-Benrath, DE) ;
Klesczewski; Bert; (Koln, DE) ; Nefzger; Hartmut;
(Pulheim, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Covestro Deutschland AG |
Leverkusen |
|
DE |
|
|
Family ID: |
53199870 |
Appl. No.: |
15/573875 |
Filed: |
May 19, 2016 |
PCT Filed: |
May 19, 2016 |
PCT NO: |
PCT/EP2016/061216 |
371 Date: |
November 14, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08G 18/482 20130101;
C08G 18/5045 20130101; C08G 18/4837 20130101; C08G 65/2618
20130101; C08G 65/2606 20130101; C08G 18/163 20130101; C08G
2101/0083 20130101; C08G 2101/005 20130101; C08G 18/1833 20130101;
B01J 19/1812 20130101; C08G 65/2663 20130101; C08G 18/7621
20130101; C08G 18/44 20130101; C08G 2101/0008 20130101; C08G 18/244
20130101; C08G 18/4018 20130101 |
International
Class: |
C08G 65/26 20060101
C08G065/26; C08G 18/40 20060101 C08G018/40; C08G 18/44 20060101
C08G018/44; C08G 18/48 20060101 C08G018/48; C08G 18/50 20060101
C08G018/50 |
Foreign Application Data
Date |
Code |
Application Number |
May 26, 2015 |
EP |
15169222.5 |
Claims
1. A process for preparing polyether polyols comprising adding
alkylene oxides onto H-functional starter compounds, wherein the
H-functional starter compound comprises at least one alcohol
containing at least two urethane groups.
2. The process as claimed in claim 1, wherein the H-functional
starter compound comprises at least one alcohol containing two
urethane groups.
3. The process as claimed in claim 2, wherein said alcohol
containing two urethane groups corresponds to the formula (II)
##STR00007## wherein: R.sup.1 represents a linear or branched
C.sub.2- to C.sub.24-alkylene which may optionally be interrupted
by heteroatoms such as O, S or N and may be substituted, R.sup.2
represents a linear or branched C.sub.2- to C.sub.24-alkylene,
C.sub.3- to C.sub.24-cycloalkylene, C.sub.4- to C.sub.24-arylene,
C.sub.5- to C.sub.24-aralkylene, C.sub.2- to C.sub.24-alkenylene,
C.sub.2- to C.sub.24-alkynylene, each of which may optionally be
interrupted by heteroatoms such as O, S or N and/or each of which
may be substituted by alkyl, aryl and/or hydroxyl, R.sup.3
represents a H atom, linear or branched C.sub.1- to C.sub.24-alkyl,
C.sub.3- to C.sub.24-cycloalkyl, C.sub.4- to C.sub.24-aryl,
C.sub.5- to C.sub.24-aralkyl, C.sub.2- to C.sub.24-alkenyl,
C.sub.2- to C.sub.24-alkynyl, each of which may optionally be
interrupted by heteroatoms such as O, S or N and/or each of which
may be substituted by alkyl, aryl and/or hydroxyl, R.sup.4
represents a H atom, linear or branched C.sub.1- to C.sub.24-alkyl,
C.sub.3- to C.sub.24-cycloalkyl, C.sub.4- to C.sub.24-aryl,
C.sub.5- to C.sub.24-aralkyl, C.sub.2- to C.sub.24-alkenyl,
C.sub.2- to C.sub.24-alkynyl, each of which may optionally be
interrupted by heteroatoms such as O, S or N and/or each of which
may be substituted by alkyl, aryl and/or hydroxyl, R.sup.5
represents a linear or branched C.sub.2- to C.sub.24-alkylene which
may optionally be interrupted by heteroatoms such as O, S or N and
may be substituted; and each of R.sup.1 to R.sup.5 may be identical
or different.
4. The process as claimed in claim 3, wherein R.sup.1 represents
CH.sub.2--CH.sub.2 or CH.sub.2--CH(CH.sub.3), R.sup.2 represents
C.sub.2- to C.sub.24-alkylene, R.sup.3 and R.sup.4=each represent a
H atom, and R.sup.5 represents CH.sub.2--CH.sub.2 or
CH.sub.2--CH(CH.sub.3).
5. The process as claimed in claim 1, wherein said alcohol
containing at least two urethane groups is obtainable by reacting
cyclic carbonates with compounds having at least two amino
groups.
6. The process as claimed in claim 1, wherein said alcohol
containing at least two urethane groups is obtainable by reacting
propylene carbonate and/or ethylene carbonate with compounds having
at least two amino groups.
7. The process as claimed in claim 1, wherein said alcohol
containing at least two urethane groups is obtainable by reacting
propylene carbonate and/or ethylene carbonate with diamines of
formula (III) HN(R.sup.3)--R.sup.2--NH(R.sup.4) (III) wherein:
R.sup.2 to R.sup.4 may be identical or different and R.sup.2
represents a linear or branched C.sub.2- to C.sub.24-alkylene,
C.sub.3- to C.sub.24-cycloalkylene, C.sub.4- to C.sub.24-arylene,
C.sub.5- to C.sub.24-aralkylene, C.sub.2- to C.sub.24-alkenylene,
C.sub.2- to C.sub.24-alkynylene, each of which may optionally be
interrupted by heteroatoms such as O, S or N and/or each of which
may be substituted by alkyl, aryl and/or hydroxyl, R.sup.3
represents a H atom, linear or branched C.sub.1- to C.sub.24-alkyl,
C.sub.3- to C.sub.24-cycloalkyl, C.sub.4- to C.sub.24-aryl,
C.sub.5- to C.sub.24-aralkyl, C.sub.2- to C.sub.24-alkenyl,
C.sub.2- to C.sub.24-alkynyl, each of which may optionally be
interrupted by heteroatoms such as O, S or N and/or each of which
may be substituted by alkyl, aryl and/or hydroxyl, and R.sup.4
represents a H atom, linear or branched C.sub.1- to C.sub.24-alkyl,
C.sub.3- to C.sub.24-cycloalkyl, C.sub.4 to C.sub.24-aryl, C.sub.5-
to C.sub.24-aralkyl, C.sub.2- to C.sub.24-alkenyl, C.sub.2- to
C.sub.24-alkynyl, each of which may optionally be interrupted by
heteroatoms such as O, S or N and/or each of which may be
substituted by alkyl, aryl and/or hydroxyl.
8. The process as claimed in claim 1, wherein said alcohol
containing at least two urethane groups is obtainable by reacting
propylene carbonate and/or ethylene carbonate with at least one
compound which comprises at least one of 1,2-ethanediamine,
diaminopropane, diaminopentane, diaminohexane, diaminooctane,
diaminodecane, diaminododecane, diaminooctadecane, diaminoeicosane,
isophoronediamine, tolylenediamine, and methylenedianiline.
9. The process as claimed in claim 1, wherein adding alkylene
oxides onto H-functional starter compounds occurs in the presence
of at least one DMC catalyst.
10. The process as claimed in claim 1, wherein adding of said
alcohol containing at least two urethane groups is effected by
metering said alcohol continuously into the reactor as H-functional
starter substance during the reaction, and wherein the resulting
reaction mixture is removed continuously from the reactor after a
preselectable mean residence time.
11. The process as claimed in claim 9, comprising initially
charging an H-functional starter polyol S--I and the double metal
cyanide catalyst into a reactor, and then continuously metering at
least one alcohol containing at least two urethane groups into this
reactor together with one or more alkylene oxides, wherein the
H-functional starter polyol S--I has an OH number in the range from
3 mg KOH/g to 1000 mg KOH/g, and wherein the resulting reaction
mixture is removed continuously from the reactor after a
preselectable mean residence time.
12. The process as claimed in claim 10, wherein DMC catalyst is
also continuously metered into the reactor.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application is a National Phase Application of
PCT/EP2016/061216, filed May 19, 2016, which claims priority to
European Application No. 15169222.5, filed May 26, 2015, each of
which are being incorporated herein by reference.
FIELD
[0002] The present invention relates to a process for preparing
polyether polyols by addition of alkylene oxides onto H-functional
starter compounds, characterized in that at least one alcohol which
contains at least two urethane groups is used as H-functional
starter compound. The invention further provides polyether polyols
containing at least two urethane groups, the polyether polyols
obtainable by the process of the invention, the use of the
polyether polyols of the invention for preparation of a
polyurethane polymer, and the resulting polyurethane polymers.
BACKGROUND
[0003] The preparation of polyether carbonate polyols by catalytic
reaction of alkylene oxides (epoxides) and carbon dioxide in the
presence of H-functional starter substances ("starters") has been
the subject of intensive study for more than 40 years (e.g. Inoue
et al., Copolymerization of Carbon Dioxide and Epoxide with
Organometallic Compounds; Die Makromolekulare Chemie 130, 210-220,
1969). This reaction is shown in schematic form in scheme (I),
where R is an organic radical such as alkyl, alkylaryl or aryl
which may in each case also contain heteroatoms, for example O, S,
Si, etc., and where e, f, g and h are each integers, and where the
product shown here in scheme (I) for the polyether carbonate polyol
should be understood as meaning merely that blocks having the
structure shown may in principle be retained in the polyether
carbonate polyol obtained but the sequence, number and length of
the blocks and the OH functionality of the starter may vary and is
not restricted to the polyether carbonate polyol shown in scheme
(I). This reaction (see scheme (I)) is highly advantageous from an
environmental standpoint since this reaction comprises converting a
greenhouse gas such as CO.sub.2 into a polymer. A further product
formed, actually a by-product, is the cyclic carbonate shown in
scheme (I) (for example propylene carbonate when R.dbd.CH.sub.3,
also referred to hereinafter as cPC, or ethylene carbonate when
R.dbd.H, also referred to hereinafter as cEC).
##STR00001##
[0004] U.S. Pat. No. 3,829,505 and DE 1 595 759 describe the
possibility of reacting OH-functional starter compounds in excess
with aromatic polyisocyanates, in order to arrive in this way at
polyurethane polyols containing OH groups and having at least 2
urethane groups, which can be used as starter oligomers for the DMC
catalysis.
[0005] U.S. Pat. No. 3,654,224 describes the possibility of using
amides, especially aromatic amides, for example benzamide, as
starter compound for the DMC catalysis.
SUMMARY
[0006] It was therefore an object of the present invention to
utilize the cyclic carbonate obtained as a by-product for the
preparation of polyether polyols. Preferably, the polyether polyols
thus obtainable are to be suitable for the preparation of
polyurethanes, especially of flexible polyurethane foams.
[0007] This object is achieved in accordance with the invention by
a process for preparing polyether polyols by addition of alkylene
oxides onto H-functional starter compounds, characterized in that
at least one alcohol containing at least two urethane groups is
used as H-functional starter compound.
[0008] Preferably, the process of the invention for preparing
polyether polyols by addition of alkylene oxides onto H-functional
starter compounds is characterized in that at least one alcohol
containing two urethane groups is used as H-functional starter
compound.
DETAILED DESCRIPTION
[0009] Particular preference is given to the process of the
invention for preparing polyether polyols by addition of alkylene
oxides onto H-functional starter compounds, characterized in that
at least one alcohol of formula (II) is used as H-functional
starter compound
##STR00002##
where [0010] R.sup.1 is linear or branched C.sub.2- to
C.sub.24-alkylene which may optionally be interrupted by
heteroatoms such as O, S or N and may be substituted, preferably
CH.sub.2--CH.sub.2 or CH.sub.2--CH(CH.sub.3), [0011] R.sup.2 is
linear or branched C.sub.2 to C.sub.24-alkylene, C.sub.3 to
C.sub.24-cycloalkylene, C.sub.4 to C.sub.24-arylene, C.sub.5 to
C.sub.24-aralkylene, C.sub.2 to C.sub.24-alkenylene, C.sub.2 to
C.sub.24-alkynylene, each of which may optionally be interrupted by
heteroatoms such as O, S or N and/or each of which may be
substituted by alkyl, aryl and/or hydroxyl, preferably C.sub.2 to
C.sub.24-alkylene, [0012] R.sup.3 is H, linear or branched C.sub.1
to C.sub.24-alkyl, C.sub.3 to C.sub.24-cycloalkyl, C.sub.4 to
C.sub.24-aryl, C.sub.5 to C.sub.24-aralkyl, C.sub.2 to
C.sub.24-alkenyl, C.sub.2 to C.sub.24-alkynyl, each of which may
optionally be interrupted by heteroatoms such as O, S or N and/or
each of which may be substituted by alkyl, aryl and/or hydroxyl,
preferably H, [0013] R.sup.4 is H, linear or branched C.sub.1 to
C.sub.24-alkyl, C.sub.3 to C.sub.24-cycloalkyl, C.sub.4 to
C.sub.24-aryl, C.sub.5 to C.sub.24-aralkyl, C.sub.2 to
C.sub.24-alkenyl, C.sub.2 to C.sub.24-alkynyl, each of which may
optionally be interrupted by heteroatoms such as O, S or N and/or
each of which may be substituted by alkyl, aryl and/or hydroxyl,
preferably H, [0014] R.sup.5 is linear or branched C.sub.2 to
C.sub.24-alkylene which may optionally be interrupted by
heteroatoms such as O, S or N and may be substituted, preferably
CH.sub.2--CH.sub.2 or CH.sub.2--CH(CH.sub.3), and where R.sup.1 to
R.sup.5 may be identical or different.
[0015] The use of the word a in connection with countable
parameters should be understood here and hereinafter to mean the
number one only when this is evident from the context (for example
through the wording "exactly one"). Otherwise, expressions such as
"an alkylene oxide", "an alcohol containing at least two urethane
groups" etc. always refer to those embodiments in which two or more
alkylene oxides, two or more alcohols containing at least two
urethane groups, etc. are used.
[0016] The invention is illustrated in detail hereinafter. Various
embodiments can be combined here with one another as desired,
unless the opposite is apparent to the person skilled in the art
from the context.
[0017] The alcohols containing at least two urethane groups are
obtainable by reacting cyclic carbonates with compounds containing
at least two amino groups. Preferably, the alcohols containing two
urethane groups are obtainable by reacting propylene carbonate
and/or ethylene carbonate with compounds containing two amino
groups.
[0018] The particularly preferred alcohols of the formula (II) are
obtainable by reacting cyclic carbonates with diamines of formula
(III)
HN(R.sup.3)--R.sup.2--NH(R.sup.4) (III)
where R.sup.2, R.sup.3 and R.sup.4 are as defined above, where
R.sup.3 and R.sup.4 may be identical or different.
[0019] Cyclic carbonates used are preferably propylene carbonate
and/or ethylene carbonate.
[0020] Most preferably, the alcohols of the formula (II) are
obtainable by reacting propylene carbonate and/or ethylene
carbonate with diamines of formula (III).
[0021] More preferably, the alcohols of the formula (II) are
obtainable by reacting propylene carbonate and/or ethylene
carbonate with at least one compound selected from the group
consisting of 1,2-ethanediamine, diaminopropane, diaminopentane,
diaminohexane, diaminooctane, diaminodecane, diaminododecane,
diaminooctadecane, diaminoeicosane, isophoronediamine,
tolylenediamine, and methylenedianiline.
[0022] The reaction of the cyclic carbonates with the compounds
containing at least two amino groups is effected preferably at 40
to 80.degree. C., more preferably at 55 to 65.degree. C. The
reaction time is preferably 5 to 40 h, more preferably 10 to 30
h.
[0023] In a particularly advantageous embodiment, the cyclic
carbonate is used in excess. Preferably, the molar ratio of cyclic
carbonate to the amino groups of the compounds containing at least
two amino groups is 1.05 to 3, more preferably from 1.1 to 2, most
preferably from 1.2 to 1.6. The excess cyclic carbonate can either
be removed directly after the synthesis of the alcohol containing
at least two urethane groups by thin-film evaporation, for example,
or can remain in the alcohol containing at least two urethane
groups and be used in the polyether polyol preparation as well. In
the second case mentioned, the excess cyclic carbonate is removed
from the product after the polyether polyol preparation.
[0024] As well as the alcohols containing at least two urethane
groups, it is additionally also possible to use H-functional
starter compounds lacking urethane groups in the process of the
invention, these being described hereinafter. Suitable H-functional
starter substances ("starters") employed may be compounds having
alkoxylation-active hydrogen atoms and having a molar mass of 18 to
4500 g/mol, preferably of 62 to 500 g/mol and more preferably of 62
to 182 g/mol. The ability to use a starter having a low molar mass
is a distinct advantage over the use of oligomeric starters
prepared by means of a prior alkoxylation. In particular, a level
of economic viability is achieved that is made possible by the
omission of a separate alkoxylation process.
[0025] Groups active in respect of the alkoxylation and having
active hydrogen atoms are, for example, --OH, --NH.sub.2 (primary
amines), --NH-- (secondary amines), --SH, and --CO.sub.2H,
preferably --OH and --NH.sub.2, more preferably --OH. H-Functional
starter substances used are, for example, one or more compounds
selected from the group consisting of mono- and polyhydric
alcohols, polyfunctional amines, polyfunctional thiols, amino
alcohols, thio alcohols, hydroxy esters, polyether polyols,
polyester polyols, polyester ether polyols, polyether carbonate
polyols, polycarbonate polyols, polycarbonates, polyethyleneimines,
polyetheramines, polytetrahydrofurans (e.g. PolyTHF.RTM. from
BASF), polytetrahydrofuran amines, polyether thiols, polyacrylate
polyols, castor oil, the mono- or diglyceride of castor oil,
monoglycerides of fatty acids, chemically modified mono-, di-
and/or triglycerides of fatty acids, and C.sub.1-C.sub.24 alkyl
fatty acid esters containing an average of at least 2 OH groups per
molecule. By way of example, the C.sub.1-C.sub.24-alkyl fatty acid
esters containing an average of at least 2 OH groups per molecule
are commercial products such as Lupranol Balance.RTM. (from BASF
AG), Merginol.RTM. products (from Hobum Oleochemicals GmbH),
Sovermol.RTM. products (from Cognis Deutschland GmbH & Co. KG)
and Soyol.RTM. TM products (from USSC Co.).
[0026] Monofunctional starter substances used may be alcohols,
amines, thiols and carboxylic acids. Monofunctional alcohols used
may be: methanol, ethanol, 1-propanol, 2-propanol, 1-butanol,
2-butanol, tert-butanol, 3-buten-1-ol, 3-butyn-1-ol,
2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2-ol, propargyl alcohol,
2-methyl-2-propanol, 1-tert-butoxy-2-propanol, 1-pentanol,
2-pentanol, 3-pentanol, 1-hexanol, 2-hexanol, 3-hexanol,
1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol,
3-octanol, 4-octanol, phenol, 2-hydroxybiphenyl, 3-hydroxybiphenyl,
4-hydroxybiphenyl, 2-hydroxypyridine, 3-hydroxypyridine,
4-hydroxypyridine. Useful monofunctional amines include:
butylamine, tert-butylamine, pentylamine, hexylamine, aniline,
aziridine, pyrrolidine, piperidine, morpholine. Monofunctional
thiols used may be: ethanethiol, 1-propanethiol, 2-propanethiol,
1-butanethiol, 3-methyl-1-butanethiol, 2-butene-1-thiol,
thiophenol. Monofunctional carboxylic acids include: formic acid,
acetic acid, propionic acid, butyric acid, fatty acids such as
stearic acid, palmitic acid, oleic acid, linoleic acid, linolenic
acid, benzoic acid, acrylic acid.
[0027] Polyhydric alcohols suitable as H-functional starter
substances are, for example, dihydric alcohols (for example
ethylene glycol, diethylene glycol, propylene glycol, dipropylene
glycol, 1,3-propanediol, 1,4-butanediol, 1,4-butenediol,
1,4-butynediol, neopentyl glycol, 1,5-pentanediol,
methylpentanediols (for example 3-methyl-1,5-pentanediol),
1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol,
bis(hydroxymethyl)cyclohexanes (for example
1,4-bis(hydroxymethyl)cyclohexane), triethylene glycol,
tetraethylene glycol, polyethylene glycols, dipropylene glycol,
tripropylene glycol, polypropylene glycols, dibutylene glycol and
polybutylene glycols); trihydric alcohols (for example
trimethylolpropane, glycerol, trishydroxyethyl isocyanurate, castor
oil); tetrahydric alcohols (for example pentaerythritol);
polyalcohols (for example sorbitol, hexitol, sucrose, starch,
starch hydrolyzates, cellulose, cellulose hydrolyzates,
hydroxy-functionalized fats and oils, especially castor oil), and
all the modification products of these aforementioned alcohols with
different amounts of .epsilon.-caprolactone.
[0028] The H-functional starter substances may also be selected
from the substance class of the polyether polyols having a
molecular weight M.sub.n in the range from 18 to 4500 g/mol and a
functionality of 2 to 3. Preference is given to polyether polyols
formed from repeat ethylene oxide and propylene oxide units,
preferably having a proportion of propylene oxide units of 35% to
100%, particularly preferably having a proportion of propylene
oxide units of 50% to 100%. These may be random copolymers,
gradient copolymers, alternating copolymers or block copolymers of
ethylene oxide and propylene oxide. More particularly, polyether
polyols obtainable by the process according to the invention
described here are used. For this purpose, these polyether polyols
used as H-functional starter substances are prepared in a separate
reaction step beforehand.
[0029] The H-functional starter substances may also be selected
from the substance class of the polyester polyols. The polyester
polyols used are at least difunctional polyesters. Preferably,
polyester polyols consist of alternating acid and alcohol units.
Acid components used are, for example, succinic acid, maleic acid,
maleic anhydride, adipic acid, phthalic anhydride, phthalic acid,
isophthalic acid, terephthalic acid, tetrahydrophthalic acid,
tetrahydrophthalic anhydride, hexahydrophthalic anhydride or
mixtures of the acids and/or anhydrides mentioned. Alcohol
components used are, for example, ethanediol, propane-1,2-diol,
propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, neopentyl
glycol, hexane-1,6-diol, 1,4-bis(hydroxymethyl)cyclohexane,
diethylene glycol, dipropylene glycol, trimethylolpropane,
glycerol, pentaerythritol or mixtures of the alcohols mentioned.
Employing dihydric or polyhydric polyether polyols as the alcohol
component affords polyester ether polyols which can likewise serve
as starter substances for preparation of the polyether carbonate
polyols.
[0030] In addition, H-functional starter substances used may be
polycarbonate diols which are prepared, for example, by reaction of
phosgene, dimethyl carbonate, diethyl carbonate or diphenyl
carbonate and difunctional alcohols or polyester polyols or
polyether polyols. Examples of polycarbonates may be found, for
example, in EP-A 1359177.
[0031] In a further embodiment of the invention, it is possible to
use polyether carbonate polyols as H-functional starter
substances.
[0032] The H-functional starter substances generally have a
functionality (i.e. the number of hydrogen atoms active in respect
of the polymerization per molecule) of 1 to 8, preferably of 2 or
3. The H-functional starter substances are used either individually
or as a mixture of at least two H-functional starter
substances.
[0033] More preferably, the H-functional starter substances are one
or more compounds selected from the group consisting of ethylene
glycol, propylene glycol, propane-1,3-diol, butane-1,3-diol,
butane-1,4-diol, pentane-1,5-diol, 2-methylpropane-1,3-diol,
neopentyl glycol, hexane-1,6-diol, octane-1,8-diol, diethylene
glycol, dipropylene glycol, glycerol, trimethylolpropane,
pentaerythritol, sorbitol and polyether polyols having a molecular
weight Mn in the range from 150 to 4500 g/mol and a functionality
of 2 to 3.
[0034] The invention further provides polyether polyols containing
a structural unit of the formula (IV)
##STR00003##
where R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are as defined
above. Preferably, the polyether polyols of the invention contain
exactly one single structural unit of the formula (IV) per
polyether polyol molecule.
[0035] The polyether polyols of the invention preferably have an OH
number of 3 to 400 mg KOH/g, more preferably 10 to 200 mg
KOH/g.
[0036] In addition, the polyether polyols of the invention have a
functionality of 2.0 to 4.0, preferably of 2.05 to 3.0.
[0037] The present invention further provides a process for
preparing polyether polyols by adding alkylene oxides onto
H-functional starter compounds, characterized in that at least one
alcohol containing at least two urethane groups, preferably an
alcohol of formula (II), is used as H-functional starter compound
and the addition is effected in the presence of at least one double
metal cyanide catalyst (also referred to as DMC catalyst).
[0038] DMC catalysts suitable for the process of the invention are
known in principle from the prior art (see, for example, U.S. Pat.
No. 3,404,109, U.S. Pat. No. 3,829,505, U.S. Pat. No. 3,941,849 and
U.S. Pat. No. 5,158,922). DMC catalysts which are described, for
example, in U.S. Pat. No. 5,470,813, EP-A-0 700 949, EP-A-0 743
093, EP-A-0 761 708, WO 97/40086, WO 98/16310 and WO 00/47649 have
a very high activity in the polymerization of alkylene oxides and,
in some cases, the copolymerization of alkylene oxides with
suitable comonomers, for example lactones, cyclic carboxylic
anhydrides, lactides, cyclic carbonates or carbon dioxide, and
enable the preparation of polymeric polyols at very low catalyst
concentrations (25 ppm or less), such that there is generally no
longer any need to separate the catalyst from the finished product.
A typical example is that of the highly active DMC catalysts which
are described in EP-A-0 700 949 and contain not only a double metal
cyanide compound (e.g. zinc hexacyanocobaltate(III)) and an organic
complex ligand (e.g. tert-butanol) but also a polyether having a
number-average molecular weight greater than 500 g/mol. It is also
possible to use the alkaline DMC catalysts disclosed in WO
2011/144523.
[0039] Cyanide-free metal salts suitable for preparation of the
double metal cyanide compounds preferably have the general formula
(V)
M(X).sub.n (V)
where
[0040] M is selected from the metal cations Zn.sup.2+, Fe.sup.2+,
Ni.sup.2+, Mn.sup.2+, Co.sup.2+, Sr.sup.2+, Sn.sup.2+, Pb.sup.2+
and Cu.sup.2+; M is preferably Zn.sup.2+, Fe.sup.2+, Co.sup.2+ or
Ni.sup.2+,
[0041] X is one or more (i.e. different) anions, preferably an
anion selected from the group of the halides (i.e. fluoride,
chloride, bromide, iodide), hydroxide, sulfate, carbonate, cyanate,
thiocyanate, isocyanate, isothiocyanate, carboxylate, oxalate and
nitrate;
[0042] n is 1 when X=sulfate, carbonate or oxalate and
[0043] n is 2 when X=halide, hydroxide, cyanate, thiocyanate,
isocyanate, isothiocyanate or nitrate;
[0044] or suitable cyanide-free metal salts have the general
formula (VI)
M.sub.r(X).sub.3 (VI)
where
[0045] M is selected from the metal cations Fe.sup.3+, Al.sup.3+
and Cr.sup.3+,
[0046] X is one or more (i.e. different) anions, preferably an
anion selected from the group of the halides (i.e. fluoride,
chloride, bromide, iodide), hydroxide, sulfate, carbonate, cyanate,
thiocyanate, isocyanate, isothiocyanate, carboxylate, oxalate and
nitrate;
[0047] r is 2 when X=sulfate, carbonate or oxalates and
[0048] r is 1 when X=halide, hydroxide, cyanate, thiocyanate,
isocyanate, isothiocyanate, carboxylate or nitrate,
[0049] or suitable cyanide-free metal salts have the general
formula (VII)
M(X).sub.s (VII)
where
[0050] M is selected from the metal cations Mo.sup.4+, V.sup.4+ and
W.sup.4+,
[0051] X is or more (i.e. different) anions, preferably an anion
selected from the group of the halides (i.e. fluoride, chloride,
bromide, iodide), hydroxide, sulfate, carbonate, cyanate,
thiocyanate, isocyanate, isothiocyanate, carboxylate, oxalate and
nitrate;
[0052] s is 2 when X=sulfate, carbonate or oxalate and
[0053] s is 4 when X=halide, hydroxide, cyanate, thiocyanate,
isocyanate, isothiocyanate, carboxylate or nitrate,
[0054] or suitable cyanide-free metal salts have the general
formula (VIII)
M(X).sub.t (VIII)
where
[0055] M is selected from the metal cations Mo.sup.6+ and
W.sup.6+,
[0056] X is one or more (i.e. different) anions, preferably an
anion selected from the group of the halides (i.e. fluoride,
chloride, bromide, iodide), hydroxide, sulfate, carbonate, cyanate,
thiocyanate, isocyanate, isothiocyanate, carboxylate, oxalate and
nitrate;
[0057] t is 3 when X=sulfate, carbonate or oxalate and
[0058] t is 6 when X=halide, hydroxide, cyanate, thiocyanate,
isocyanate, isothiocyanate, carboxylate or nitrate.
[0059] Examples of suitable cyanide-free metal salts are zinc
chloride, zinc bromide, zinc iodide, zinc acetate, zinc
acetylacetonate, zinc benzoate, zinc nitrate, iron(II) sulfate,
iron(II) bromide, iron(II) chloride, cobalt(II) chloride,
cobalt(II) thiocyanate, nickel(II) chloride and nickel(II) nitrate.
It is also possible to use mixtures of different metal salts.
[0060] Metal cyanide salts suitable for preparation of the double
metal cyanide compounds preferably have the general formula
(IX)
(Y).sub.aM'(CN).sub.b(A).sub.c (IX)
where
[0061] M' is selected from one or more metal cations from the group
consisting of Fe(II), Fe(III), Co(II), Co(III), Cr(II), Cr(III),
Mn(II), Mn(III), Ir(III), Ni(II), Rh(III), Ru(II), V(IV) and V(V);
M' is preferably one or more metal cations from the group
consisting of Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III)
and Ni(II),
[0062] Y is selected from one or more metal cations from the group
consisting of alkali metal (i.e. Li.sup.+, Na.sup.+, K.sup.+,
Rb.sup.+, Cs.sup.+) and alkaline earth metal (i.e. Be.sup.2+,
Ca.sup.2+, Mg.sup.2+, Sr.sup.2+, Ba.sup.2+)
[0063] A is selected from one or more anions of the group
consisting of halides (i.e. fluoride, chloride, bromide, iodide),
hydroxide, sulfate, carbonate, cyanate, thiocyanate, isocyanate,
isothiocyanate, carboxylate, oxalate or nitrate and
[0064] a, b and c are integers, the values for a, b and c being
selected such as to ensure the electronic neutrality of the metal
cyanide salt; a is preferably 1, 2, 3 or 4; b is preferably 4, 5 or
6; c preferably has the value 0.
[0065] Examples of suitable metal cyanide salts are potassium
hexacyanocobaltate(III), potassium hexacyanoferrate(II), potassium
hexacyanoferrate(III), calcium hexacyanocobaltate(III) and lithium
hexacyanocobaltate(III).
[0066] Preferred double metal cyanide compounds present in the DMC
catalysts are compounds of general formula (X)
Mx[M'x,(CN)y]z (X)
in which M is defined as in formula (V) to (VIII) and
[0067] M' is as defined in formula (IX), and
[0068] x, x', y and z are integers and are chosen so as to ensure
electronic neutrality of the double metal cyanide compound.
[0069] Preferably,
[0070] x=3, x'=1, y=6 and z=2,
[0071] M=Zn(II), Fe(II), Co(II) or Ni(II) and
[0072] M'=Co(III), Fe(III), Cr(III) or Ir(III).
[0073] Examples of suitable double metal cyanide compounds are zinc
hexacyanocobaltate(III), zinc hexacyanoiridate(III), zinc
hexacyanoferrate(III) and cobalt(II) hexacyanocobaltate(III).
Further examples of suitable double metal cyanide compounds can be
found, for example, in U.S. Pat. No. 5,158,922 (column 8, lines
29-66). Particular preference is given to using zinc
hexacyanocobaltate(III).
[0074] The organic complex ligands added in the preparation of the
DMC catalysts are disclosed, for example, in U.S. Pat. No.
5,158,922 (see especially column 6 lines 9 to 65), U.S. Pat. No.
3,404,109, U.S. Pat. No. 3,829,505, U.S. Pat. No. 3,941,849, EP-A-0
700 949, EP-A-0 761 708, JP-A-4145123, U.S. Pat. No. 5,470,813,
EP-A-0 743 093 and WO-A-97/40086. The organic complex ligands used
are, for example, water-soluble organic compounds containing
heteroatoms such as oxygen, nitrogen, phosphorus or sulfur, which
can form complexes with the double metal cyanide compound.
Preferred organic complex ligands are alcohols, aldehydes, ketones,
ethers, esters, amides, ureas, nitriles, sulfides and mixtures
thereof. Particularly preferred organic complex ligands are
aliphatic ethers (such as dimethoxyethane), water-soluble aliphatic
alcohols (such as ethanol, isopropanol, n-butanol, isobutanol,
sec-butanol, tert-butanol, 2-methyl-3-buten-2-ol and
2-methyl-3-butyn-2-ol), compounds which contain both aliphatic or
cycloaliphatic ether groups and aliphatic hydroxyl groups (for
example ethylene glycol mono-tert-butyl ether, diethylene glycol
mono-tert-butyl ether, tripropylene glycol monomethyl ether and
3-methyl-3-oxetanemethanol). Extremely preferred organic complex
ligands are selected from one or more compounds of the group
consisting of dimethoxyethane, tert-butanol 2-methyl-3-buten-2-ol,
2-methyl-3-butyn-2-ol, ethylene glycol mono-tert-butyl ether and
3-methyl-3-oxetanemethanol.
[0075] Optionally used in the preparation of the DMC catalysts are
one or more complex-forming component(s) from the compound classes
of the polyethers, polyesters, polycarbonates, polyalkylene glycol
sorbitan esters, polyalkylene glycol glycidyl ethers,
polyacrylamide, poly(acrylamide-co-acrylic acid), polyacrylic acid,
poly(acrylic acid-co-maleic acid), polyacrylonitrile, polyalkyl
acrylates, polyalkyl methacrylates, polyvinyl methyl ethers,
polyvinyl ethyl ethers, polyvinyl acetate, polyvinyl alcohol,
poly-N-vinylpyrrolidone, poly(N-vinylpyrrolidone-co-acrylic acid),
polyvinyl methyl ketone, poly(4-vinylphenol), poly(acrylic
acid-co-styrene), oxazoline polymers, polyalkyleneimines, maleic
acid and maleic anhydride copolymers, hydroxyethyl cellulose and
polyacetals, or of the glycidyl ethers, glycosides, carboxylic
esters of polyhydric alcohols, gallic acids or salts, esters or
amides thereof, cyclodextrins, phosphorus compounds,
.alpha.,.beta.-unsaturated carboxylic esters or ionic surface- or
interface-active compounds.
[0076] Preferably, in the preparation of the DMC catalysts, in the
first step, the aqueous solutions of the metal salt (e.g. zinc
chloride), used in a stoichiometric excess (at least 50 mol %)
based on metal cyanide salt (i.e. at least a molar ratio of
cyanide-free metal salt to metal cyanide salt of 2.25:1.00), and
the metal cyanide salt (e.g. potassium hexacyanocobaltate) are
converted in the presence of the organic complex ligand (e.g.
tert-butanol), such that a suspension is formed comprising the
double metal cyanide compound (e.g. zinc hexacyanocobaltate),
water, excess cyanide-free metal salt, and the organic complex
ligands. This organic complex ligand may be present in the aqueous
solution of the cyanide-free metal salt and/or of the metal cyanide
salt, or it is added directly to the suspension obtained after
precipitation of the double metal cyanide compound. It has been
found to be advantageous to mix the aqueous solutions of the
cyanide-free metal salt and of the metal cyanide salt and the
organic complex ligands by stirring vigorously. Optionally, the
suspension formed in the first step is subsequently treated with a
further complex-forming component. The complex-forming component is
preferably used in a mixture with water and organic complex ligand.
A preferred process for performing the first step (i.e. the
preparation of the suspension) comprises using a mixing nozzle,
particularly preferably using a jet disperser, as described in
WO-A-01/39883.
[0077] In the second step, the solid (i.e. the precursor of the
inventive catalyst) is isolated from the suspension by known
techniques, such as centrifugation or filtration.
[0078] In a preferred execution variant for preparing the catalyst,
the isolated solid is subsequently washed in a third process step
with an aqueous solution of the organic complex ligand (for example
by resuspension and subsequent reisolation by filtration or
centrifugation). In this way, it is possible to remove, for
example, water-soluble by-products such as potassium chloride from
the catalyst. Preferably, the amount of the organic complex ligand
in the aqueous wash solution is between 40% and 80% by weight,
based on the overall solution.
[0079] Further complex-forming component is optionally added to the
aqueous wash solution in the third step, preferably in the range
between 0.5% and 5% by weight, based on the overall solution.
[0080] It is moreover advantageous to wash the isolated solid more
than once. For this purpose, for example, the first washing
procedure can be repeated. It is preferable, however, to use
non-aqueous solutions for further washing operations, e.g. a
mixture of organic complex ligands and other complex-forming
components.
[0081] The isolated and optionally washed solid is subsequently,
optionally after pulverization, dried at temperatures of generally
20-100.degree. C. and at pressures of generally 0.1 mbar to
standard pressure (1013 mbar).
[0082] A preferred process for isolating the DMC catalysts from the
suspension by filtration, filtercake washing and drying is
described in WO-A-01/80994.
[0083] The concentration of DMC catalyst used is 5.0 ppm to 1000
ppm, preferably 10 ppm to 900 ppm and more preferably 20 ppm to 80
ppm, based on the mass of the polyether polyol to be prepared.
According to the profile of requirements for the downstream use,
the DMC catalyst can be left in the product or (partly) removed.
The (partial) removal of the DMC catalyst can be effected, for
example, by treatment with adsorbents. Methods of removing DMC
catalysts are described, for example, in U.S. Pat. No. 4,987,271,
DE-A-3132258, EP-A-0 406 440, U.S. Pat. No. 5,391,722, U.S. Pat.
No. 5,099,075, U.S. Pat. No. 4,721,818, U.S. Pat. No. 4,877,906 and
EP-A-0 385 619.
[0084] Alkylene oxides suitable for the process of the invention
have 2 to 24 carbon atoms. The alkylene oxides having 2 to 24
carbon atoms are preferably one or more compounds selected from the
group consisting of ethylene oxide, propylene oxide, 1-butene
oxide, 2,3-butene oxide, 2-methyl-1,2-propene oxide (isobutene
oxide), 1-pentene oxide, 2,3-pentene oxide, 2-methyl-1,2-butene
oxide, 3-methyl-1,2-butene oxide, 1-hexene oxide, 2,3-hexene oxide,
3,4-hexene oxide, 2-methyl-1,2-pentene oxide, 4-methyl-1,2-pentene
oxide, 2-ethyl-1,2-butene oxide, 1-heptene oxide, 1-octene oxide,
1-nonene oxide, 1-decene oxide, 1-undecene oxide, 1-dodecene oxide,
4-methyl-1,2-pentene oxide, butadiene monoxide, isoprene monoxide,
cyclopentene oxide, cyclohexene oxide, cycloheptene oxide,
cyclooctene oxide, styrene oxide, methylstyrene oxide, pinene
oxide, mono- or polyalkylene oxidized fats as mono-, di- and
triglycerides, alkylene oxidized fatty acids, C.sub.1-C.sub.24
esters of alkylene oxidized fatty acids, epichlorohydrin, glycidol,
and derivatives of glycidol, for example methyl glycidyl ether,
ethyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl
ether, and alkylene oxide-functional alkyloxysilanes, for example
3-glycidyloxypropyltrimethoxysilane,
3-glycidyloxypropyltriethoxysilane,
3-glycidyloxypropyltripropoxysilane,
3-glycidyloxypropylmethyldimethoxysilane,
3-glycidyloxypropylethyldiethoxysilane and
3-glycidyloxypropyltriisopropoxysilane. The alkylene oxide used is
preferably at least one alkylene oxide selected from the group
consisting of ethylene oxide and propylene oxide.
[0085] Further monomers copolymerizable with alkylene oxides by the
process of the invention under DMC catalysis are all
oxygen-containing cyclic compounds, especially lactones, lactides,
aliphatic and aromatic cyclic carboxylic anhydrides and cyclic
carbonates. The use thereof is described in U.S. Pat. No.
3,538,043, U.S. Pat. No. 4,500,704, U.S. Pat. No. 5,032,671, U.S.
Pat. No. 6,646,100, EP-A-0 222 453 and WO-A-2008/013731.
[0086] A number of variants for performance of the process of the
invention are described in detail hereinafter. The illustration is
merely by way of example and should not be understood such that it
restricts the present invention.
[0087] In a preferred embodiment of the invention (variant A), at
least one alcohol containing at least two urethane groups,
preferably an alcohol of the formula (II), and the double metal
cyanide catalyst are first initially charged and then the alkylene
oxide is added.
[0088] Variant A) ("Semi-Batchwise Procedure"):
[0089] In variant A) of the process of the invention, at least one
alcohol containing at least two urethane groups, preferably an
alcohol of the formula (II), is first initially charged together
with the DMC catalyst in a reactor/reactor system. It is optionally
possible to add small amounts of an inorganic mineral acid,
preferably phosphoric acid, to the alcohol containing at least two
urethane groups prior to contacting with the DMC catalyst, as
described in applications WO-A-99/14258 and EP-A-1 577 334, in
order to neutralize any traces of base in the alcohol containing at
least two urethane groups, preferably an alcohol of the formula
(II), or in order to generally stabilize the production process.
After heating to temperatures of 50.degree. C. to 160.degree. C.,
preferably 60.degree. C. to 140.degree. C., most preferably
70.degree. C. to 140.degree. C., in a preferred process variant,
the reactor contents are stripped with inert gas while stirring
over a period of preferably 10 to 60 min. In the course of
stripping with inert gas, volatile constituents, for example traces
of water, are removed with introduction of inert gases into the
liquid phase with simultaneous application of reduced pressure, at
an absolute pressure of 5 mbar to 500 mbar. After metered addition
of typically 5% by weight to 20% by weight of one or more alkylene
oxides, based on the amount of alcohol containing at least two
urethane groups, preferably an alcohol of the formula (II),
initially charged, the DMC catalyst is activated. The addition of
one or more alkylene oxides may precede, coincide with or follow
the heating of the reactor contents to temperatures of 50.degree.
C. to 160.degree. C., preferably 60.degree. C. to 140.degree. C.,
most preferably 70.degree. C. to 140.degree. C.; it preferably
follows after the stripping. The activation of the catalyst is
noticeable by an accelerated drop in the reactor pressure, which
indicates the commencement of alkylene oxide conversion. The
desired amount of alkylene oxide or alkylene oxide mixture can then
be supplied continuously to the reaction mixture, and a reaction
temperature of 20.degree. C. to 200.degree. C., preferably of
50.degree. C. to 160.degree. C., more preferably 70.degree. C. to
150.degree. C., most preferably 80.degree. C. to 140.degree. C., is
chosen. The reaction temperature is in many cases identical to the
activation temperature; alternatively, it can be altered on
completion of catalyst activation, for example in order not to
subject sensitive starter compounds to excessive thermal stress. It
is often the case that catalyst activation is effected so quickly
that the metered addition of a separate amount of alkylene oxide
for catalyst activation can be dispensed with and it is possible to
commence directly, optionally at first with a reduced metering
rate, with the continuous metered addition of one or more alkylene
oxides. The reaction temperature may also be varied within the
limits described over the entire alkylene oxide metering phase. The
alkylene oxides can likewise be supplied to the reactor in
different ways: one option is metered addition into the gas phase
or directly into the liquid phase, for example by means of an
immersed tube or a distributor ring close to the reactor base in a
zone with good mixing. In the case of DMC-catalyzed processes,
metered addition in the liquid phase is frequently the preferred
variant. The one or more alkylene oxide(s) should be fed
continuously to the reactor in such a way that the safety-related
pressure limits of the reactor system used are not exceeded.
Especially in the case of metered co-addition of ethylene
oxide-containing alkylene oxide mixtures or pure ethylene oxide, it
should be ensured that a sufficient partial inert gas pressure is
maintained within the reactor during the startup and metering
phase. This can be established, for example, by means of noble
gases or nitrogen. In the case of metered addition into the liquid
phase, the metering units should be designed such that they
self-empty, for example through provision of metering holes on the
underside of the distributor ring. Generally, apparatus measures,
for example the installation of non-return valves, should prevent
backflow of reaction medium into the metering units and reactant
reservoirs. If an alkylene oxide mixture is being metered in, the
respective alkylene oxides can be supplied to the reactor
separately or as a mixture. Premixing of the alkylene oxides with
one another can be achieved, for example, by means of a mixing unit
present in the common metering zone ("inline blending"). It has
also been found to be useful to meter the alkylene oxides, on the
pump pressure side, individually or in premixed form into a pumped
circulation system conducted, for example, through one or more heat
exchangers. In that case, for good mixing with the reaction medium,
it is advantageous to integrate a high-shear mixing unit into the
alkylene oxide/reaction medium stream. The temperature of the
exothermic ring-opening addition reaction is kept at the desired
level by cooling. According to the prior art relating to design of
polymerization reactors for exothermic reactions (for example
Ullmann's Encyclopedia of Industrial Chemistry, vol. B4, pp. 167
ff., 5th ed., 1992), such cooling is generally effected via the
reactor wall (e.g. jacket, half-coil pipe) and by means of further
heat exchange surfaces disposed internally in the reactor and/or
externally in the pumped circulation system, for example in cooling
coils, cooling cartridges, or plate, shell-and-tube or mixer heat
exchangers. This cooling should be designed such that effective
cooling is possible even on commencement of the metering phase,
i.e. with a low fill level.
[0090] Generally, good mixing of the reactor contents should be
ensured in all reaction phases through design and use of standard
stirring units, suitable stirring units here being especially
stirrers arranged over one or more levels or stirrer types which
act over the full fill height, for example gate stirrers (see, for
example, Handbuch Apparate [Apparatus Handbook]; Vulkan-Verlag
Essen, 1st ed. (1990), p. 188-208). Of particular technical
relevance here is a specific mixing power which is introduced on
average over the entire reactor contents and is generally in the
range from 0.2 W/L to 5 W/L, based on the reactor volume, with
correspondingly higher local power inputs in the region of the
stirrer units themselves and possibly in the case of relatively low
fill levels. In order to achieve optimal stirring action,
combinations of baffles (for example flat or tubular baffles) and
cooling coils (or cooling cartridges) may be arranged within the
reactor according to the general prior art, and these may also
extend over the vessel base. The stirring power of the mixing unit
may also be varied as a function of the fill level during the
metering phase, in order to ensure a particularly high energy input
in critical reaction phases. Preference is given to using stirrer
units with stirrer levels close to the base. In addition, the
stirrer geometry should contribute to reducing the foaming of
reaction products. The foaming of reaction mixtures can be
observed, for example, after the end of the metering and
post-reaction phase, when residual alkylene oxides are additionally
removed under reduced pressure, at absolute pressures in the range
from 1 mbar to 500 mbar. For such cases, suitable stirrer units
have been found to be those which achieve continuous mixing of the
liquid surface. According to the requirement, the stirrer shaft has
a base bearing and optionally further support bearings in the
vessel. The stirrer shaft can be driven from the top or bottom
(with central or eccentric arrangement of the shaft).
[0091] Alternatively, it is also possible to achieve the necessary
mixing exclusively by means of a pumped circulation system
conducted through a heat exchanger, or to operate this pumped
circulation system as a further mixing component in addition to the
stirrer unit, in which case the reactor contents are pumped in
circulation as required (typically 1 to 50 times per hour). The
specific mixing energy introduced by means of pumped circulation,
for example by means of an external heat exchanger or, in the case
of recycling into the reactor, by means of a nozzle or injector,
likewise amounts to values averaging from 0.2 to 5 W/L, this being
based on the liquid volume present in the reactor and the pumped
circulation system at the end of the reaction phase.
[0092] A wide variety of different reactor types is suitable for
the performance of the process of the invention. Preference is
given to using cylindrical vessels having a height/diameter ratio
of 1.0:1 to 10:1. Useful reactor bases include hemispherical,
dished, flat or conical bases.
[0093] The end of the metered addition of the one or more alkylene
oxides may be followed by a postreaction phase in which residual
alkylene oxide is depleted. The end of this postreaction phase has
been attained when no further pressure drop can be detected in the
reaction tank. Traces of unreacted alkylene oxides, after the
reaction phase, can optionally be removed quantitatively under
reduced pressure, at an absolute pressure of 1 mbar to 500 mbar, or
by stripping. Stripping removes volatile constituents, for example
(residual) alkylene oxides, with introduction of inert gases or
steam into the liquid phase with simultaneous application of
reduced pressure, for example by passing inert gas through at an
absolute pressure of 5 mbar to 500 mbar. The removal of volatile
constituents, for example of unconverted alkylene oxides, either
under reduced pressure or by stirring, is effected at temperatures
of 20.degree. C. to 200.degree. C., preferably at 50.degree. C. to
160.degree. C., and preferably with stirring. Such stripping
operations can also be performed in what are called stripping
columns, in which an inert gas or steam stream is passed counter to
the product stream. Preference is given to performing the stripping
operation with inert gases in the absence of steam.
[0094] After constant pressure has been attained or after volatile
constituents have been removed by reduced pressure and/or
stripping, the product obtained by the process of the invention can
be discharged from the reactor.
[0095] A characteristic of DMC catalysts is their marked
sensitivity to high concentrations of hydroxyl groups which are
caused in standard industrial scale processes for polyether polyol
production, for example, by high proportions of starters such as
ethylene glycol, propylene glycol, glycerol, trimethylolpropane,
sorbitol or sucrose that are present in the reaction mixture at the
start of the reaction, and polar impurities in the reaction mixture
or the starter(s). In that case, the DMC catalysts cannot be
converted to the polymerization-active form during the reaction
initiation phase. Impurities may, for example, be water, compounds
having a high number of hydroxyl groups closely adjacent to one
another, such as carbohydrates and carbohydrate derivatives, or
compounds having basic groups, for example amines. For the process
of the invention, it is of particular significance that even
substances having urethane groups adjacent to hydroxyl groups do
not have an adverse effect on the catalyst activity. In order
nevertheless to be able to subject starters having a high
concentration of OH groups, or starters having impurities
considered to be catalyst poisons, or starters having arrangements
of functional groups that have a disadvantageous effect on catalyst
activity, to DMC-catalyzed alkylene oxide addition reactions, the
hydroxyl group concentration has to be lowered, the starter
concentration has to be reduced, and the catalyst poisons have to
be rendered harmless. For this purpose, for example, it is possible
first to use these starter compounds to prepare, by means of basic
catalysis, prepolymers which, after workup, are then converted by
means of DMC catalysis to the desired alkylene oxide addition
products of high molar mass. A disadvantage of this procedure is
that such prepolymers often obtained by means of basic catalysis
have to be worked up very carefully, in order to rule out
deactivation of the DMC catalyst by traces of basic catalyst
entrained by the prepolymers.
[0096] These disadvantages can be overcome by the method of
continuous metered addition of starter, which is disclosed in
WO-A-97/29146. In this case, critical compounds are not initially
charged in the reactor but supplied continuously to the reactor
during the reaction in addition to the alkylene oxides. Starting
media, or what are called H-functional starter polyols S--I, for
the reaction which may be initially charged in this process are
alkylene oxide addition products of H-functional starter compounds,
for example including those without urethane groups. It is also
possible to use the polyether polyol prepared by the process of the
invention itself, which has been prepared separately beforehand, as
the starting medium (S--I). There is thus no need to first
separately prepare prepolymers suitable for further alkylene oxide
additions.
[0097] Variant B) ("CAOS Semi-Batchwise Procedure"):
[0098] In variant B) of the process of the invention, an
H-functional starter polyol S--I and the DMC catalyst are initially
charged in the reactor system, and at least one alcohol containing
at least two urethane groups, preferably an alcohol of the formula
(II), is fed in continuously together with one or more alkylene
oxides. Suitable H-functional starter polyols S--I for this variant
are alkylene oxide addition products, for example polyether
polyols, polycarbonate polyols, polyestercarbonate polyols or
polyethercarbonate polyols, each, for example, with OH numbers in
the range from 3.0 mg KOH/g to 1000 mg KOH/g, preferably from 3.0
mg KOH/g to 300 mg KOH/g, and/or a polyether polyol prepared
separately by the process of the invention. Preference is given to
using a polyether polyol prepared separately by the process of the
invention as H-functional starter polyol S--I.
[0099] The metered addition of the at least one alcohol containing
at least two urethane groups, preferably an alcohol of the formula
(II), and the one or more alkylene oxide(s) is preferably ended
simultaneously, or the alcohol containing at least two urethane
groups, preferably an alcohol of the formula (II), and a first
portion of one or more alkylene oxide(s) are first metered in
together and then the second portion of one or more alkylene oxides
is metered in, the sum total of the first and second portions of
one or more alkylene oxides corresponding to the total amount of
the one or more alkylene oxides used. The first portion is
preferably 60% by weight to 98% by weight and the second portion is
40% by weight to 2% by weight of the total amount of one or more
alkylene oxides to be metered in. If the composition of the
alkylene oxide metering stream is altered after the end of the
metered addition of the alcohol containing at least two urethane
groups, preferably an alcohol of the formula (II), it is also
possible to prepare products having multiblock structures by
process variant B). The metered addition of the reagents may be
followed by a postreaction phase in which the consumption of
alkylene oxide can be quantified by monitoring the pressure. On
attainment of constant pressure, optionally after application of
reduced pressure or by stripping to remove unconverted alkylene
oxides, as described above, the product can be discharged.
[0100] It is alternatively also possible, in variant B of the
process of the invention, in addition to the alcohol containing at
least two urethane groups, preferably an alcohol of the formula
(II), also to use the above-described H-functional starter
compounds which are not alcohols containing at least two urethane
groups in a continuous manner together with one or more alkylene
oxides.
[0101] Variant C ("Continuous CAOS Procedure"):
[0102] In a further preferred embodiment of the process of the
invention (variant C), an H-functional starter polyol S--I and a
portion of the double metal cyanide catalyst are initially charged,
and then at least one alcohol containing at least two urethane
groups, preferably an alcohol of the formula (II), and further
double metal cyanide catalyst are fed in continuously together with
the alkylene oxide, with continuous withdrawal of the polyether
polyol formed here from the reaction system after a preselectable
mean residence time.
[0103] In variant C) of the process of the invention, the polyether
polyols are prepared in a fully continuous manner. A fully
continuous process for preparing alkylene oxide addition products
is described in principle in WO-A-98/03571. The procedure disclosed
therein is applicable to the performance of the process of the
invention. In this variant, as well as one or more alkylene oxides
and at least one alcohol containing at least two urethane groups,
preferably an alcohol of the formula (II), the DMC catalyst is also
fed continuously to the reactor or a reactor system under
alkoxylation conditions, and the polyether polyol is withdrawn
continuously from the reactor or the reactor system after a
preselectable mean residence time. For startup of such a fully
continuous process, a starter polyol S--I and a portion of the DMC
catalyst are initially charged. Suitable starter polyols S--I for
variant C) of the process of the invention are alkylene oxide
addition products, for example polyether polyols, polycarbonate
polyols, polyestercarbonate polyols, polyethercarbonate polyols,
for example, with OH numbers in the range from 3.0 mg KOH/g to 1000
mg KOH/g, preferably from 3.0 mg KOH/g to 300 mg KOH/g, and/or a
polyether polyol prepared by the process of the invention, which
has been prepared separately beforehand. Preference is given to
using polyether polyol prepared by the process of the invention
which has previously been prepared separately as starter polyol in
variant C of the process of the invention.
[0104] For example, the reactor is operated in such a way that it
has been filled completely with the reaction mixture ("liquid-full"
mode).
[0105] Continuous postreaction steps may follow, for example in a
reactor cascade or a tubular reactor. The volatile constituents can
be removed under reduced pressure and/or by stripping, as described
above.
[0106] For example, in a subsequent step, the reaction mixture
removed continuously, which generally has an alkylene oxide content
of from 0.05% by weight to 10% by weight, may be transferred into a
postreactor in which, by way of a postreaction, the content of free
alkylene oxide is reduced to less than 0.05% by weight in the
reaction mixture. The postreactor may be a tubular reactor, a loop
reactor or a stirred tank for example. The pressure in this
postreactor is preferably at the same pressure as in the reaction
apparatus in which the preceding reaction step of the addition of
the alkylene oxides onto alcohols containing at least two urethane
groups, preferably alcohols of the formula (II), is performed. The
temperature in the downstream reactor is preferably 50.degree. C.
to 150.degree. C. and more preferably 80.degree. C. to 140.degree.
C.
[0107] In particularly preferred embodiments of variants B and C of
the process of the invention, the starter polyol S--I used is a
polyether polyol of the invention or a polyether polyol obtainable
by the process of the invention.
[0108] The present invention further provides a polyether polyol
obtainable by the process of the invention.
[0109] The OH numbers of the polyether polyols obtained preferably
have values of 3 mg KOH/g to 400 mg KOH/g, more preferably of 10 mg
KOH/g to 200 mg KOH/g, most preferably of 20 mg KOH/g to 150 mg
KOH/g. This is true irrespective of the process variant used (A, B
or C).
[0110] The equivalent molar mass is understood to mean the total
mass of the material containing active hydrogen atoms divided by
the number of active hydrogen atoms.
[0111] In the case of materials containing hydroxyl groups, it is
in the following relationship with the OH number:
equivalent molar mass=56 100/OH number [mg KOH/g]
[0112] It is optionally possible to add ageing stabilizers, for
example antioxidants, to the polyether polyols obtainable by the
process according to the invention.
[0113] The present invention further relates to the use of a
polyether polyol of the invention for preparation of a polyurethane
polymer, preferably a flexible polyurethane foam, more preferably a
flexible slabstock polyurethane foam or a flexible molded
polyurethane foam.
[0114] The present invention further provides a polyurethane
polymer, preferably a flexible polyurethane foam, more preferably a
flexible slabstock polyurethane foam or a flexible molded
polyurethane foam, obtainable by reacting a polyisocyanate with a
polyether polyol of the invention by a method familiar to the
person skilled in the art, with the aid of standard additives, for
example activators, stabilizers, blowing agents, crosslinkers,
chain extenders and/or fillers, and optionally further polyether
polyols, polyester polyols, polyethercarbonate polyols,
polycarbonate polyols and/or filler-containing polyols (polymer
polyols, polyurea dispersions, etc.).
[0115] Suitable polyisocyanates are aliphatic, cycloaliphatic,
araliphatic, aromatic and heterocyclic polyisocyanates, as
described, for example, by W. Siefken in Justus Liebigs Annalen der
Chemie, 562, pages 75 to 136, for example those of the formula
(XI)
Q(NCO).sub.n, (XI)
in which [0116] n=2-4, preferably 2-3, [0117] and [0118] Q is an
aliphatic hydrocarbyl radical having 2-18 and preferably 6-10
carbon atoms, a cycloaliphatic hydrocarbyl radical having 4-15 and
preferably 6-13 carbon atoms or an araliphatic hydrocarbyl radical
having 8-15 and preferably 8-13 carbon atoms.
[0119] For example, the polyisocyanates are those as described in
EP 0 007 502 A1, pages 7-8. Preference is generally given to the
readily industrially available polyisocyanates, for example
tolylene 2,4- and 2,6-diisocyanate and any desired mixtures of
these isomers ("TDI"); polyphenylpolymethylene polyisocyanates as
prepared by aniline-formaldehyde condensation and subsequent
phosgenation ("crude MDI"), and polyisocyanates having carbodiimide
groups, urethane groups, allophanate groups, isocyanurate groups,
urea groups or biuret groups ("modified polyisocyanates"),
especially those modified polyisocyanates which derive from
tolylene 2,4- and/or 2,6-diisocyanate or from diphenylmethane 4,4'-
and/or 2,4'-diisocyanate. The polyisocyanates containing urethane
groups (prepolymers) may, for example, be reaction products of the
polyisocyanates with polyester polyols or else any other polyols
(for example conventional polyether polyols). The polyisocyanate
used is preferably at least one compound selected from the group
consisting of tolylene 2,4- and 2,6-diisocyanate, diphenylmethane
4,4'- and 2,4'- and 2,2'-diisocyanate and polyphenylpolymethylene
polyisocyanate ("multiring MDI"); the polyisocyanate used is more
preferably a mixture comprising diphenylmethane 4,4'-diisocyanate
and diphenylmethane 2,4'-diisocyanate and polyphenylpolymethylene
polyisocyanate.
[0120] As well as the aforementioned polyisocyanates, it is
additionally also possible to use conventional polyether polyols
for the preparation of the polyurethane polymers. Conventional
polyether polyols in the context of the invention are understood to
mean the alkylene oxide addition products of starter compounds
having Zerewitinoff-active hydrogen atoms. Examples of such
polyether polyols are known to those skilled in the art. They may
have a hydroxyl number to DIN 53240 of .gtoreq.3.0 mg KOH/g to
.ltoreq.1000 mg KOH/g, preferably of .gtoreq.5.0 mg KOH/g to
.ltoreq.600 mg KOH/g. The starter compounds having
Zerewitinoff-active hydrogen atoms used for the preparation of the
conventional polyether polyols usually have functionalities of 2 to
8. The starter compounds may be hydroxy-functional and/or
amino-functional. Examples of hydroxy-functional starter compounds
are propylene glycol, ethylene glycol, diethylene glycol,
dipropylene glycol, butane-1,2-diol, butane-1,3-diol,
butane-1,4-diol, hexanediol, pentanediol, 3-methylpentane-1,5-diol,
dodecane-1,12-diol, glycerol, trimethylolpropane, triethanolamine,
pentaerythritol, sorbitol, sucrose, hydroquinone, catechol,
resorcinol, bisphenol F, bisphenol A, 1,3,5-trihydroxybenzene,
methylol-containing condensates of formaldehyde and phenol or
melamine or urea. Examples of amino-functional starter compounds
are ammonia, ethanolamine, diethanolamine, triethanolamine,
isopropanolamine, diisopropanolamine, ethylenediamine,
hexamethylenediamine, aniline, the isomers of toluidine, the
isomers of diaminotoluene, the isomers of diaminodiphenylmethane,
and higher polycyclic products obtained in the condensation of
aniline with formaldehyde to give diaminodiphenylmethane.
[0121] Suitable alkylene oxides for the conventional polyether
polyols are, for example, ethylene oxide, propylene oxide,
1,2-butylene oxide or 2,3-butylene oxide and styrene oxide.
Preference is given to feeding propylene oxide and ethylene oxide
into the reaction mixture individually, in a mixture or
successively. If the alkylene oxides are metered in successively,
the products produced contain polyether chains having block
structures. Products having ethylene oxide end blocks are
characterized, for example, by elevated concentrations of primary
end groups which impart advantageous isocyanate reactivity to the
systems.
[0122] The preparation of the conventional polyether polyols may be
base-catalyzed, for example via alkali metal hydroxide or amine
catalysis, double metal cyanide-catalyzed, or acid-catalyzed by
Lewis or Bronsted acids.
[0123] As well as the aforementioned conventional polyether
polyols, it is additionally or alternatively also possible to use
polyester polyols for the preparation of the polyurethane polymers.
Suitable polyester polyols preferably have OH numbers in the range
from 6 to 800 mg KOH/g and can be prepared, for example, from
polyfunctional carboxylic acids, preferably organic dicarboxylic
acids having 2 to 12 carbon atoms, and polyhydric alcohols,
preferably diols, having 2 to 12 carbon atoms, preferably 2 to 6
carbon atoms, by known methods. Rather than the polyfunctional
carboxylic acids, it is also possible to use derivatives thereof,
for example acid chlorides or anhydrides.
[0124] In a first embodiment, the invention thus relates to a
process for preparing polyether polyols by addition of alkylene
oxides onto H-functional starter compounds, characterized in that
at least one alcohol containing at least two urethane groups is
used as H-functional starter compound.
[0125] In a second embodiment, the invention relates to a process
according to the first embodiment, characterized in that at least
one alcohol containing two urethane groups is used as H-functional
starter compound.
[0126] In a third embodiment, the invention relates to a process
according to the second embodiment, characterized in that at least
one alcohol containing two urethane groups of formula (II) is used
as H-functional starter compound
##STR00004##
where [0127] R.sup.1 is linear or branched C.sub.2 to
C.sub.24-alkylene which may optionally be interrupted by
heteroatoms such as O, S or N and may be substituted, preferably
CH.sub.2--CH.sub.2 or CH.sub.2--CH(CH.sub.3), [0128] R.sup.2 is
linear or branched C.sub.2 to C.sub.24-alkylene, C.sub.3 to
C.sub.24-cycloalkylene, C.sub.4 to C.sub.24-arylene, C.sub.5 to
C.sub.24-aralkylene, C.sub.2 to C.sub.24-alkenylene, C.sub.2 to
C.sub.24-alkynylene, each of which may optionally be interrupted by
heteroatoms such as O, S or N and/or each of which may be
substituted by alkyl, aryl and/or hydroxyl, preferably C.sub.2 to
C.sub.24-alkylene, [0129] R.sup.3 is H, linear or branched C.sub.1
to C.sub.24-alkyl, C.sub.3 to C.sub.24-cycloalkyl, C.sub.4 to
C.sub.24-aryl, C.sub.5 to C.sub.24-aralkyl, C.sub.2 to
C.sub.24-alkenyl, C.sub.2 to C.sub.24-alkynyl, each of which may
optionally be interrupted by heteroatoms such as O, S or N and/or
each of which may be substituted by alkyl, aryl and/or hydroxyl,
preferably H, [0130] R.sup.4 is H, linear or branched C.sub.1 to
C.sub.24-alkyl, C.sub.3 to C.sub.24-cycloalkyl, C.sub.4 to
C.sub.24-aryl, C.sub.5 to C.sub.24-aralkyl, C.sub.2 to
C.sub.24-alkenyl, C.sub.2 to C.sub.24-alkynyl, each of which may
optionally be interrupted by heteroatoms such as O, S or N and/or
each of which may be substituted by alkyl, aryl and/or hydroxyl,
preferably H, [0131] R.sup.5 is linear or branched C.sub.2 to
C.sub.24-alkylene which may optionally be interrupted by
heteroatoms such as O, S or N and may be substituted, preferably
CH.sub.2--CH.sub.2 or CH.sub.2--CH(CH.sub.3), and where R.sup.1 to
R.sup.5 may be identical or different.
[0132] In a fourth embodiment, the invention relates to a process
according to the third embodiment, where [0133]
R.sup.1.dbd.CH.sub.2--CH.sub.2 or CH.sub.2--CH(CH.sub.3), [0134]
R.sup.2.dbd.C.sub.2 to C.sub.24-alkylene, [0135]
R.sup.3.dbd.R.sup.4.dbd.H, and [0136]
R.sup.5.dbd.CH.sub.2--CH.sub.2 or CH.sub.2--CH(CH.sub.3).
[0137] In a fifth embodiment, the invention relates to a process
according to any of embodiments 1 to 4, characterized in that the
alcohol containing at least two urethane groups is obtainable by
reacting cyclic carbonates with compounds having at least two amino
groups.
[0138] In a sixth embodiment, the invention relates to a process
according to any of embodiments 1 to 5, characterized in that the
alcohol containing at least two urethane groups is obtainable by
reacting propylene carbonate and/or ethylene carbonate with
compounds having at least two amino groups.
[0139] In a seventh embodiment, the invention relates to a process
according to any of embodiments 1 to 6, characterized in that the
alcohol containing two urethane groups is obtainable by reacting
propylene carbonate and/or ethylene carbonate with diamines of
formula (III)
HN(R.sup.3)--R.sup.2--NH(R.sup.4) (III)
where R.sup.2 to R.sup.4 may be identical or different and may be
as defined in embodiments 3 and 4.
[0140] In an eighth embodiment, the invention relates to a process
according to any of embodiments 1 to 7, characterized in that the
alcohol containing two urethane groups is obtainable by reacting
propylene carbonate and/or ethylene carbonate with at least one
compound selected from the group consisting of 1,2-ethanediamine,
diaminopropane, diaminopentane, diaminohexane, diaminooctane,
diaminodecane, diaminododecane, diaminooctadecane, diaminoeicosane,
isophoronediamine, tolylenediamine, and methylenedianiline.
[0141] In a ninth embodiment, the invention relates to a process
according to any of embodiments 1 to 8, characterized in that the
alkylene oxide used is at least one alkylene oxide selected from
the group consisting of ethylene oxide and propylene oxide.
[0142] In a tenth embodiment, the invention relates to a process
according to any of embodiments 1 to 9, wherein the addition is
effected in the presence of at least one DMC catalyst.
[0143] In an eleventh embodiment, the invention relates to a
process according to embodiment 10, wherein at least one alcohol
containing at least two urethane groups and the double metal
cyanide catalyst are first initially charged and then the alkylene
oxide is added.
[0144] In a twelfth embodiment, the invention relates to a process
according to any of embodiments 1 to 11, wherein alcohol containing
at least two urethane groups is metered continuously into the
reactor as H-functional starter compound during the reaction, and
wherein the resulting reaction mixture is removed continuously from
the reactor after a preselectable mean residence time.
[0145] In a thirteenth embodiment, the invention relates to a
process according to embodiment 10, wherein an H-functional starter
polyol S--I and the double metal cyanide catalyst are initially
charged in a reactor and then at least one alcohol containing at
least two urethane groups is metered continuously into this reactor
together with one or more alkylene oxides, wherein the H-functional
starter polyol S--I has an OH number in the range from 3 mg KOH/g
to 1000 mg KOH/g, and wherein the resulting reaction mixture is
removed continuously from the reactor after a preselectable mean
residence time.
[0146] In a fourteenth embodiment, the invention relates to a
process according to embodiment 12 or 13, wherein DMC catalyst is
additionally also metered continuously into the reactor.
[0147] In a fifteenth embodiment, the invention relates to a
process according to any of embodiments 12 to 14, wherein the
reaction mixture removed continuously from the reactor with a
content of 0.05% by weight to 10% by weight of alkylene oxide is
transferred into a postreactor in which, by way of a postreaction,
the content of free alkylene oxide is reduced to less than 0.05% by
weight in the reaction mixture.
[0148] In a sixteenth embodiment, the invention relates to a
process according to embodiment 13, characterized in that the
starter polyol S--I used is a polyether polyol containing a
structural unit of the formula (IV)
##STR00005##
where R.sup.1 to R.sup.5 may be identical or different and are as
defined in claims 3 and 4, or a polyether polyol obtainable by a
process according to any of embodiments 1 to 15.
[0149] In a seventeenth embodiment, the invention relates to
polyether polyols containing a structural unit of the formula
(IV)
##STR00006##
where R.sup.1 to R.sup.5 may be identical or different and are as
defined in embodiments 3 and 4.
[0150] In an eighteenth embodiment, the invention relates to
polyether polyols according to embodiment 17, characterized in that
these have an OH number in the range from 3 to 400 mg KOH/g,
preferably from 10 to 200 mg KOH/g.
[0151] In a nineteenth embodiment, the invention relates to
polyether polyols obtainable by a process according to any of
embodiments 1 to 16.
[0152] In a twentieth embodiment, the invention relates to the use
of a polyether polyol according to any of embodiments 17 to 19 for
preparation of a polyurethane polymer, preferably a flexible
polyurethane foam.
[0153] In a twenty-first embodiment, the invention relates to a
polyurethane polymer, preferably a flexible polyurethane foam,
obtainable by reacting a polyisocyanate with a polyether polyol
according to any of embodiments 17 to 19.
EXAMPLES
[0154] Test Methods:
[0155] Experimentally determined OH numbers were determined by the
method of DIN 53240.
[0156] The amine numbers (NH number) were determined by the method
of DIN 53176.
[0157] The viscosities were determined by means of a rotary
viscometer (Physica MCR 51, manufacturer: Anton Paar) by the method
of DIN 53018.
[0158] The determination of the functionality of the starter in the
finished polyether polyol was conducted by means of .sup.13C NMR
(from Bruker, Advance 400, 400 MHz; wait time d1: 4 s, 6000 scans).
Each sample was dissolved in deuterated acetone-D6 with addition of
chromium(III) acetylacetonate. The solution concentration was 500
mg/mL.
[0159] The relevant resonances in the .sup.13C NMR (based on
CHCl.sub.3=7.24 ppm) are as follows:
[0160] The carbon signals of the carbon atoms bonded directly to
the nitrogen (methylene groups, methine group) of the starter are
evaluated:
[0161] Bifunctionally started: 40.4 ppm to 40.0 ppm (one
carbon)
[0162] Tri- and tetrafunctionally started: 42.2 ppm to 40.5 ppm
(two carbons)
[0163] Bifunctionally started means that only the OH groups of the
diurethane diol starter compound are alkoxylated.
[0164] Tri- and tetrafunctionally started means that the OH groups
and one or both of the NH groups of the urethane bond of the
diurethane diol starter compound are alkoxylated.
[0165] The chemical shifts in the .sup.13C NMR were determined by
comparative measurements (comparative spectra).
[0166] The apparent densities and the compression hardnesses (40%
compression, 4.sup.th cycle) were determined to DIN EN ISO
3386-1.
[0167] Raw Materials Used:
[0168] Catalyst for the Alkylene Oxide Addition (DMC Catalyst):
[0169] Double metal cyanide catalyst, containing zinc
hexacyanocobaltate, tert-butanol and polypropylene glycol having a
number-average molecular weight of 1000 g/mol, according to example
6 in WO-A 01/80994.
[0170] Cyclic propylene carbonate (cPC): from Acros.
[0171] Cyclic ethylene carbonate (cEC): from Acros.
[0172] 1,3-Diaminopropane, Sigma-Aldrich
[0173] 1,5-Diaminopentane, Sigma-Aldrich
[0174] Stabilizer 1: siloxane-based foam stabilizer, Tegostab.RTM.
BF 2370, Evonik Goldschmidt
[0175] Isocyanate 1: mixture of 80% by weight of tolylene 2,4- and
20% by weight of tolylene 2,6-diisocyanate, available under the
Desmodur.RTM. T 80 name, Bayer MaterialScience AG
[0176] Catalyst 1: bis(2-dimethylaminoethyl) ether in dipropylene
glycol, available as Addocat.RTM. 108, from Rheinchemie
[0177] Catalyst 2: tin(II) ethylhexanoate, available as Dabco.RTM.
T-9, from Air Products
[0178] Preparation of Diurethane Diols:
[0179] The alcohols of the invention prepared in examples 1 and 2
contain two hydroxyl groups and two urethane groups, and are
therefore referred to as diurethane diols.
Example 1
[0180] A 2 L four-neck flask having a reflux condenser and
thermometer was initially charged with cyclic propylene carbonate
(919 g, 9 mol). Subsequently, 1,3-diaminopropane (222 g, 3 mol) was
gradually added dropwise at 60.degree. C. The reaction was
subsequently stirred at 60.degree. C. for a further 24 h in total.
After cooling to 25.degree. C., the diurethane diol was
obtained.
[0181] Product properties of the resulting diurethane diol:
[0182] OH number: 295 mg KOH/g
[0183] NH number: 0.8 mg KOH/g
[0184] Viscosity (25.degree. C.): 2000 mPas
Example 2
[0185] A 2 L four-neck flask with reflux condenser and thermometer
was initially charged with cyclic propylene carbonate (766 g, 7.5
mol). Subsequently, 1,5-diaminopentane (255 g, 2.5 mol) was
gradually added dropwise. The reaction was subsequently stirred at
60.degree. C. for a further 24 h in total. After cooling to
25.degree. C., the diurethane diol was obtained.
[0186] Product properties of the resulting diurethane diol:
[0187] OH number: 278 mg KOH/g
[0188] NH number: 0.9 mg KOH/g
[0189] Viscosity (25.degree. C.): 2100 mPas
Preparation of Polyether Polyols
Example 3 (Semi-Batchwise CAOS Method)
[0190] A 2 liter stainless steel pressure reactor was initially
charged with 200 g of a trifunctional
poly(oxypropylene-oxyethylene) polyol having an ethylene oxide
content of 10.5% (Arcol.RTM. polyol 1108) and OH number=48 mg KOH/g
and 234 mg of DMC catalyst under nitrogen, and heated to
130.degree. C. Stripping was accomplished by introducing nitrogen
into the reaction mixture at 130.degree. C. for a period of 30 min
and simultaneously applying a reduced pressure (in absolute terms),
such that a reduced pressure of 0.1 bar (absolute) was established
in the reactor. Then, at 130.degree. C. while stirring (800 rpm),
20 g of propylene oxide were first metered into the reactor within
5 min. Subsequently, over a period of 6 h, 781 g of propylene oxide
and 179 g of diurethane diol from example 1 were metered into the
reactor at 130.degree. C. while stirring (800 rpm). Finally, at
130.degree. C. while stirring (800 rpm), a further 20 g of
propylene oxide were metered into the reactor within 10 min. After
a postreaction time of 90 min at 130.degree. C., volatile
constituents were distilled off under reduced pressure at 50 mbar
(absolute) and 130.degree. C. for 60 minutes and then the reaction
mixture was cooled to room temperature.
[0191] Product Properties:
[0192] OH number: 49.3 mg KOH/g
[0193] Viscosity (25.degree. C.): 1348 mPas
Example 4 (Semi-Batchwise CAOS Method)
[0194] A 2 liter stainless steel pressure reactor was initially
charged with 200 g of the polyether polyol from example 3 and 200
mg of DMC catalyst under nitrogen, and heated to 130.degree. C.
Stripping was accomplished by introducing nitrogen into the
reaction mixture at 130.degree. C. for a period of 30 min and
simultaneously applying a reduced pressure (in absolute terms),
such that a reduced pressure of 0.1 bar (absolute) was established
in the reactor. Then, at 130.degree. C. while stirring (800 rpm),
20 g of propylene oxide were first metered into the reactor within
5 min. Subsequently, over a period of 6.5 h, 782 g of propylene
oxide and 178 g of diurethane diol from example 1 were metered into
the reactor at 130.degree. C. while stirring (800 rpm). Finally, at
130.degree. C. while stirring (800 rpm), a further 20 g of
propylene oxide were metered into the reactor within 10 min. After
a postreaction time of 45 min at 130.degree. C., volatile
constituents were distilled off under reduced pressure at 50 mbar
(absolute) and 130.degree. C. for 60 minutes and then the reaction
mixture was cooled to room temperature.
[0195] Product Properties:
[0196] OH number: 47.5 mg KOH/g
[0197] Viscosity (25.degree. C.): 1410 mPas
Example 5 (Semi-Batchwise CAOS Method)
[0198] A 2 liter stainless steel pressure reactor was initially
charged with 200 g of the polyether polyol from example 4 and 200
mg of DMC catalyst under nitrogen, and heated to 130.degree. C.
Stripping was accomplished by introducing nitrogen into the
reaction mixture at 130.degree. C. for a period of 30 min and
simultaneously applying a reduced pressure (in absolute terms),
such that a reduced pressure of 0.1 bar (absolute) was established
in the reactor. Then, at 130.degree. C. while stirring (800 rpm),
20 g of propylene oxide were first metered into the reactor within
5 min. Subsequently, over a period of 7 h, 770 g of propylene oxide
and 190 g of diurethane diol from example 2 were metered into the
reactor at 130.degree. C. while stirring (800 rpm). Finally, at
130.degree. C. while stirring (800 rpm), a further 20 g of
propylene oxide were metered into the reactor within 10 min. After
a postreaction time of 60 min at 130.degree. C., volatile
constituents were distilled off under reduced pressure at 50 mbar
(absolute) and 130.degree. C. for 60 minutes and then the reaction
mixture was cooled to room temperature.
[0199] Product Properties:
[0200] OH number: 44.8 mg KOH/g
[0201] Viscosity (25.degree. C.): 1495 mPas
Example 6 (Semi-Batchwise CAOS Method)
[0202] A 2 liter stainless steel pressure reactor was initially
charged with 195 g of the polyether polyol from example 5 and 20 mg
of DMC catalyst under nitrogen, and heated to 130.degree. C.
Stripping was accomplished by introducing nitrogen into the
reaction mixture at 130.degree. C. for a period of 30 min and
simultaneously applying a reduced pressure (in absolute terms),
such that a reduced pressure of 0.1 bar (absolute) was established
in the reactor. Then, at 130.degree. C. while stirring (800 rpm),
20 g of propylene oxide were first metered into the reactor within
5 min. Subsequently, over a period of 7 h, 759 g of propylene oxide
and 206 g of diurethane diol from example 2 were metered into the
reactor at 130.degree. C. while stirring (800 rpm). Finally, at
130.degree. C. while stirring (800 rpm), a further 20 g of
propylene oxide were metered into the reactor within 10 min. After
a postreaction time of 90 min at 130.degree. C., volatile
constituents were distilled off under reduced pressure at 50 mbar
(absolute) and 130.degree. C. for 60 minutes and then the reaction
mixture was cooled to room temperature.
[0203] Product Properties:
[0204] OH number: 49.1 mg KOH/g
[0205] Viscosity (25.degree. C.): 1438 mPas
[0206] Functionality: 2.07
Production of Flexible Polyurethane Foams
Examples 7 & 8: (with Polyether Polyols from Example 4 and
Example 6)
[0207] In a mode of processing by the one-stage method which is
customary for the production of polyurethane foams, the in the
examples of the feedstocks listed in table 1 below were reacted
with one another.
[0208] Polyurethane foams were produced according to the recipes
specified in the table below. The proportions of the components are
listed in parts by weight. High-quality flexible foams having
homogeneous cell structure were obtained, which were characterized
by determining the apparent densities and compression
hardnesses.
TABLE-US-00001 TABLE 1 Preparation of flexible polyurethane foams
Example 7a 7b 8a 8b Polyol from example 4 100 100 -- -- Polyol from
example 6 -- -- 100 100 Stabilizer 1 1.2 1.2 1.2 1.2 Catalyst 1
0.15 0.12 0.15 0.12 Catalyst 2 0.12 0.18 0.12 0.18 Water 2.50 4.50
2.50 4.50 Isocyanate 1 34.1 55.0 34.4 55.2 NCO index 104 106 104
106 Apparent density (kg/m.sup.3) 41.2 28.0 37.4 25.6 Compression
hardness, 4th cycle 4.1 4.1 3.4 4.2 (kPa)
[0209] Examples 7a, 7b, 8a and 8b demonstrate that the polyether
polyols of the invention are suitable for the production of
polyurethanes (here: flexible polyurethane foams).
* * * * *